Treatment of adult patients with acute lymphoblastic leukemia in the Czech Republic in the period 2007-2020

Abstract

Background: Pediatric-inspired protocols with prospective monitoring of minimal residual disease (MRD) are considered the standard of intensive treatment for adults with acute lymphoblastic leukemia (ALL). They have been used in the Czech Republic since 2007.

Patients and methods: Two hundred and ninety-seven patients aged 18-65 years were treated at five hematology centers between 2007-2020 according to the GMALL 07/2003 protocol. This is a retrospective analysis of their treatment outcomes.

Results: In the Ph-negative cohort, 189 (93.1%) patients achieved complete remission, 5 (2.4%) patients were refractory, and early mortality was 3.0%. Seventy (34.5%) patients experienced relapse in a median of 10.6 months. Overall survival (OS) at 3 and 5 years was 63.5% and 55.9%, disease-free survival (DFS) at 3 and 5 years was 54.5% and 49.7%, respectively. Young adults under 35 years of age (P = 0.015), patients without initial CNS infiltration (P = 0.016), with MRD negativity before consolidation treatment (P < 0.001), transplanted in the 1st complete remission (P < 0.001), and subjects treated after 2012 (P = 0.05) had significantly better overall survival. In a multivariate analysis, MRD at week 11 was the only independent factor affecting OS (HR 3.06; P = 0.006). For DFS, baseline CNS infiltration (HR 2.08; P = 0.038) and MRD at week 11 (HR 2.15; P = 0.020) were significant. In the Ph-positive cohort, 84 (89.4%) patients achieved complete remission, 1 (1.0%) patient was refractory, early mortality was 4.3%. Twenty-six (27.7%) patients relapsed in a median of 8.6 months. Survival at 3 and 5 years was 57.2% and 52.4% for OS and 50.2% and 44.9% for DFS, respectively. Transplanted patients and patients diagnosed after 2012 had statistically better overall survival (P < 0.001).

Conclusion: The introduction of pediatric-inspired protocols with treatment intensification according to MRD levels resulted in a significant improvement in the survival outcomes of adult patients with ALL.

Keywords: acute lymphoblastic leukemia; hematopoietic stem cell transplantation; minimal residual disease; pediatric-inspired protocol; treatment; type 2 diabetes.